Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

It'll be cold and cloudy at lower elevations, while the upper elevations get cooked in the sunshine. If you're sinking deeply into wet, heavy snow on a steep slope, you will likely trigger a wet avalanche. Widespread rollerballs mean it is probably time to move off steep, sunny slopes and out from under rocks and cliffs shedding snow. 

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Many areas throughout the East Central zone have already experienced a warm-up, but temperatures above the inversion will notch up again on Tuesday. So slopes in the sunshine on southern and western aspects that still hold dry snow will quickly get weat and heavy, leading to natural and triggered wet loose avalanches. These avalanches tend to initiate from your equipment as you travel or from rocks, cliffs, and trees shedding snow onto steep slopes below. Move out from under these overhead hazards if you begin to see rollerballs or the snow feels wet and heavy. If you're traveling on slopes where you begin to sink deeply into wet snow, move to shadier slopes or stick to lower-angle terrain choices. 

    There are a few crusts and persistent weak layers in our snowpack, and as temperatures warm, these can lead to more unusual avalanches and rapidly changing conditions. Wet loose avalanches may run farther and faster than you anticipate on slick crusts, and you might even begin to see slab avalanches failing on these weak layers. Watch for signs of instability and use quick hand pit tests and steep, small test slopes to see how the snow reacts. The snowpack is going through a big change, so consider choosing simpler terrain with low-angle options and little exposure to overhead hazards. 

    (1/5/2025)

    A natural wet slab avalanche in the Salmon La Sac Drainage during Sunday's warm storm. 

    Photo: Payton Schiff

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    If you're using Tuesday's clear, sunny weather to travel into alpine terrain, you could transition from wet snow problems to dry snow problems at upper elevations. You could trigger wind slabs in areas below corniced ridgelines, confined gullies, and the base of cliffs. Textured surfaces and pillowlike drifts are good visual clues to identify likely wind slab locations. Shooting cracks in stiff, wind-drifted snow is a clear sign that you should avoid steep, wind-drifted terrain. 

    Recent snow accumulated over surface hoar, slick crusts, and weak faceted layers. If you are traveling in dry snow without surface crusts, frequently assess the recent snow using small test slopes and quick hand pits. If you find the snow slides easily, back off steep terrain objectives and choose lower-angle slopes.

    (1/3/2025)

    A human-triggered avalanche near White Pass. This slide broke widely and was triggered from further back on the ridge. [N 5500']

Avalanche Discussion

On Tuesday, it will be a tale of two different worlds at upper and lower elevations. Under the inversion, lower elevations will likely stay cold and socked in, while upper elevations might feel like a sunny, spring day. Where you are within the zone could also greatly affect the snowpack and avalanche conditions you experience. Pay attention to whether the snow surfaces are wet or dry to determine if wet avalanches or storm and wind slabs should be your primary concern. We expect more dry snow avalanches in the northern and eastern portions of the zone, with more wet snow problems to the west and south. 

On Sunday, an NWAC forecaster in the Salmon La Sac area reported widespread natural avalanche activity throughout the terrain. Lower elevations saw many wet loose and wet slab avalanches, and ridgelines were peppered with an abundance of small crowns. These avalanches were primarily small, likely involving just the recent snow. But it's a testament to the weak surface hoar layer recently buried. We expect most of this activity to have run it's course during the warm temperatures and peak precipitation, especially after cool nights formed surface crusts. 

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